Eh, when a technician in our trade, or actually in most industries, tells you that there is only one way to fix something and that is to replace the whole thing (the motherboard in this case) it actually means that it is the easiest way.
That's like taking your computer that's full of viruses and gunk to a PC guy and he tells you that the only way to fix it is to format the system and delete everything on it. That's the most straightforward and easiest way The reason he tells you this is usually cause he can't charge you enough to spend some 5 hours cleaning out your computer, instead he can charge you $20 to do the format and do that in half an hour while he can do something else.
If you're going to replace the entire motherboard anyway might as well try taking it to some electronics genius and have him take a look at it and see if he can replace it.
The technician told you the fastest and simplest way to do it, but it is also the most expensive one, all technicians are like this and it's necessarily a bad thing a lot of the time, especially for people that don't have the time to wait around for a fix or people who aren't very comfortable with tech but of course this is also the most expensive one.
A few months back we had a similar situation. We have a printer that uses fiber optic cables as a connection form the PC to the motherboard. The port where you screw the cable in broke and we were pretty much ****ed. Just getting the technician there would probably cost us $1k as the only competent one is some 350km (a bit over 200 miles) away. What we did instead was phone around and found a guy that works with fiber optics for a local ISP. He came the same night, replaced the jack, welded the cables together (the welder for fiber optic cables is a pretty cool, precise little thing). We took him to a nice dinner, had some drinks and gave him $100 as a thank you.
If we had gone the technician route we would have probably had to buy $500-1000 worth of stuff and have waited for it for like a few weeks, and we were in a pretty big job at the time.